Detection of blaOXA-23 and blaNDM-1 carbapenemase among clinical isolates of A. baumannii in Tabriz, north-west of Iran

Abstract

ObjectivesDuring recent years, multidrug-resistant Acinetobacter baumannii strains have become a serious threat to global health. Furthermore, the appearance of new resistant markers, such as New Delhi metallo-β-lactamase (NDM-1) with the ability to hydrolyze a wide range of β-lactams has limited the treatment process. AimThis cross-sectional study was aimed to detect blaOXA-23 and blaNDM-1 carbapenemase genes among A. baumannii clinical isolates in Tabriz, North-west Iran. MethodsA total of 100 A. baumannii isolates were collected from Imam Reza Hospital of Tabriz city. Isolates were recognized by standard biochemical tests and molecular detection of blaOXA-51 gene. Antimicrobial susceptibility profile was examined via the disk diffusion method. The presence of blaOXA-23 and blaNDM-1 resistance genes was determined by PCR and sequencing. ResultsOverall, the highest resistance rate was against ciprofloxacin (95%), aztreonam (90%) and imipenem (82%) whereas the highest susceptibility was detected to gentamicin (65%). The frequency of MDR and XDR strains was 76% and 30%, respectively. All of carbapenem resistant isolates were carrying blaOXA-23 gene and only one of them (1%) was positive for blaNDM-1 resistance gene. ConclusionOur results are indicating a high incidence of blaOXA-23 like gene and the emergence of blaNDM-1 gene as a resistance factor to almost all antibiotics among the carbapenem resistant A. baumannii strains in our study region.